The invention relates to cathode ray tubes. In particular, the invention relates to materials, configurations, and construction for funnel-shaped envelopes of cathode ray tubes.
Cathode ray tubes are used in a variety of applications, such as but not limited to, displays, monitors, televisions, computer displays (also known as monitors), radar screens, and other such devices. Cathode ray tubes generally comprise a funnel-shaped envelope (hereinafter referred to as a xe2x80x9cfunnel envelopexe2x80x9d), an electron gun portion, and a display panel. Electrons are generated in the electron gun portion, formed into an electron beam that is passed through the inside of the funnel envelope, and impinged onto the display panel. The display panel includes a screen that is often coated with a phosphor so that the electron beam causes the phosphors to fluoresce and emit light. Thus, images can be viewed on the display panel when the cathode ray tube is in use.
Initially, cathode ray tubes were formed with metallic funnel envelopes. The metal funnel envelopes were heavy, cumbersome, and made the resulting device using the cathode ray tube device heavy to transport. Further, the costs associated with metallic funnel envelopes are high, and accordingly the cost of the associated cathode ray tube is high. The costs increase with the size of the cathode ray tube, thus as demands for larger displays are increasing the costs of the cathode ray tubes will also increase.
Metallic funnel envelopes have been replaced with glass funnel envelopes. The use of glass funnel envelopes were desirable as glass provided the funnel envelope and the associated cathode ray tube with a useful combination of lower costs, and enhanced mechanical, electrical, physical, and optical properties. Glass funnel envelopes for cathode ray tubes can provide lighter-weight cathode ray tubes and associated devices using the glass cathode ray tube. This lower weight is desirable as the portability of devices using cathode ray tubes, such as, but not limited to, television, computers and laptop computers, is steadily increasing.
Computer systems now generate, and can output, large amounts of information. This increase of generated information has lead to a need for larger computer displays (also known as monitors) using cathode ray tubes to view the information. Larger cathode ray tube displays will increase the amount of glass used in the cathode ray tube funnel envelope, and a cathode ray tube weight increase follows. A larger cathode ray tube will need an increase in funnel envelope length, which may not be desirable due to spatial restraints, for example in laptop computers. Accordingly, the overall weight and length of the funnel envelope and cathode ray tube will increase, and this weight increase is not desirable, as portability of computing systems is still very desirable. Further, the television market is also following the trend toward larger display panels, which leads to heavier and deeper cathode ray tubes, each of which consumers would like to avoid.
Therefore, a need exists to reduce the weight of a cathode ray tube while maintaining or increasing its display size. Also, a need exists to provide a cathode ray tube funnel envelope with a lower weight and length.
The invention sets forth a cathode ray tube that comprises a funnel envelope. The funnel envelope comprises thixotropic magnesium.
The invention also sets forth a cathode ray tube that comprises a funnel envelope. The funnel envelope comprises thixotropic aluminum.
Further, the invention sets forth a cathode ray tube that comprises a funnel envelope. The funnel envelope comprises thixotropic materials.
The invention sets forth a cathode ray tube that comprises a funnel envelope. The funnel envelope comprises a thixotropic material selected from thixotropic magnesium, thixotropic magnesium alloys, thixotropic aluminum, thixotropic aluminum alloys, and mixtures thereof and combinations thereof.
These and other aspects, advantages and salient features of the invention will become apparent from the following detailed description, which, when taken in conjunction with the annexed drawings, where like parts are designated by like reference characters throughout the drawings, disclose embodiments of the invention.